Yieldable pitman for mowing-machines.



E. BERNSTEIN. YIELDABLE PITMAN FOR MOWING MACHINES.

4 APPLICATION FILED SEPT. 26, 1909,

980,400, Patented Jan. 3, 1911.

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THE mamas PETERS col, WASHINGTON, n. c

EMIL BERNSTEIN, OF NAUENDORF, GERMANY.

YIELDABLE PITMAN FOR, MOWING-IVIACHINES.

To all whom it may concern:

Be it known that I, EMIL BERNs'rnIN, a subject of the King of Prussia, residing at N auendorf, Prussia, Germany, have invented certain new and useful Improvements in Yieldable Pitmen for Mowing-Machines, of

j which the following is a specification.

This invention relates to mowing-machines and more particularly to a device for immediately stopping the revolving cutters when any hard body gets against or between the same, so that the breaking of the cutters is prevented.

The several parts of the device are known by themselves but their combination and application for the purpose mentioned are new.

The invention is shown by way of example in the accompanying drawings.

Figure 1 represents the connecting rod in elevation, which is shown in Fig. 2 in longitudinal section. Fig. 3 represents part of the yieldable pitman. Fig. 4 shows the driving parts; Fig. 5 represents the sliding guide piece and Fig. 6 is a longitudinal section which represents the driving device.

The connecting rod is composed of two parts, the rod proper a and the guide rails (Z and c. The rod proper a is threaded at one end upon which the driving piece I) and the guide piece 0 are screwed. The two guide rails cl and e are made of U iron and serve to guide the sliding piece 0.

The driving device is mounted upon the rail (Z; it consists of a flat iron 1" which acts like a lever and has a notch m. The lever r is pivoted at s and the bolt around which it pivots can be adjusted by means of a screw 12. At its free end the lever r carries the thumb screw 00, which is mounted so that it does not interfere with the oscillating motion of the lever. In the rail cl a pressure spring {I is located in a suitable opening covered by a casing 0, which spring. can be adjusted by means of the regulating screw 7) and serves for pressing the lever r upon the driving piece 6.

The device operates as follows :If a hard body gets between the revolving cutters a much greater pressure or traction is exerted upon the connecting rod than usual. An

Specification of Letters Patent.

Application filed September 25, 1909.

Patented Jan. 3, 1911. Serial No. 519,626.

ordinary connecting rod therefore would at once break if the cutters are not broken. With the connecting rod constructed according to the present invention however the increase of pressure is transferred by the driving piece 6 upon the walls of the notch m of the lever 1" which thus is pressed against the spiral spring 9. The spring 9 being compressed the lever yields under the increase of pressure and the driving piece 6 jumps out of the notch we, so that the connecting rod moves in its guide rails without further driving the revolving cutters, which thus are uncoupled. After the hard body has been removed from between the cutters the driving piece 6 is again inserted .in the notch m and the mechanism is ready for operation. In order to facilitate the coupling of the connecting rod with the driving piece for the cutters the lever 1" is lifted by means of the screw bolt at so that the driving piece 5 can be inserted in the notch m without any difficulty. Said screw bolt on further serves for limiting the oscillating motion of the lever r so that the same is prevented from getting into or between the parts of the connect-ing rod.

I claim A yieldable pitman for mowing machines, comprising in combination a rod having a threaded end, a guide rail composed of two irons in which the free end of the pitman is located, a sliding guide piece screwed upon the threaded end of said rod, and sliding in the guide rail, a coupling tooth screwed upon said threaded part, a lever having a notch for the reception of the coupling tooth and pivoted with one end to the upper flange of the guide rail, and an adjustable spiral spring inserted bet-ween said guide rail and said lever for yieldably holding the lever in operative engagement with the coupling tooth, substantially as described and shown and for the purpose set forth.

In witness whereof I have hereunto set my hand in the presence of two witnesses.

EMIL BERNSTEIN.

Vitnesses RUDOLPH FRioKE, SOUTI-IARD P. WARNER. 

